January Babies and the Future of Football

The visualization explores if "relative age phenomenon" is verifiable even for soccer major teams.
Malcolm Gladwell - in his "Outliers" book - describes how he found a very high concentration of hock...
ey-players born in the first months of the year, paricularly in the youngest leagues.
This is supposed to be because of the sport selection rules of the western system: children are divided into classes based by the year of birth: "bigger" ones are most likely selected for higher leagues and so have more chances to practice at higher levels while they're growing, this ends up in a huge disproportion in the distribution of months of birth even in the NHL.
In our visualization we selected 29 European soccer teams and explore for both:
- First Team (dark pink triangles below)
- Second team (orange triangles above), youger players.
(sum for each month are on the extreme right of the visualization)
Teams are ordered orizzontally according to their market value.
For each First team (vertical lines above the central matrix) we then explored other parameters such as the average eight, age, number of foreigners players.